Okay. I've compared the two leading Stop plans, and I think the situation is going to be a tough, desperately close thing either way. Plan: And with Swiftness--Swiftness Beyond Measure... is slightly ahead for me.
It has its downsides-I'm less concerned about Valerie's foresight, but more about Aboleath's. Traps and other complications feel plausible at this point. Something like a standing order of "Clothes, protect me" might be possible.
It also lacks specific provisions for handling Lilly's family possibly taking action, or using the new Ethos if Lilly can get a decent handle on it, as unlikely as that is.
On the other hand, I interpret the emphasis on speed as trying to avoid Valerie giving another order, something like "Don't look away." or "You'll be next." Which seems likely. Lilly's also smart enough to try to stop her family if they attack or try to injure themselves, especially with her senses and 360 degree vision.
We have the estimated distance of 3 meters across a room, and Lilly's own estimation of a {Sample Space} guided {Pulse Surge} taking a tenth of a second to move her about half the distance toward someone slightly less than 3 meters away, the remaining tenth put toward summoning and swinging the {Heartstaff} at a high-speed arrow. With [Tremendous Mechanist] in play here, this feels like getting to Valerie with a degree of assuredness is possible. The specified duration of {Sample Space} leaves things open for more {Sample Space} or {The Ladder} to warn or guide Lilly. The rest of the plan includes reasonable steps for finishing the situation, while still giving Lilly some flexibility on other points.
As mentioned, it's still going to be really, really close, with possible problems still coming up. Not puncturing Lilly's eardrums could be a mistake here. A rough, rough estimate of average speaking rates is 4 syllables per second, and "No", "Sit", "Kneel" or "Die" are single syllable words. Granted, "Die" might not be first on the table for Lilly depending on how Harvesting works, but the concept is there. Fortunately, I don't think Valerie is trained as an auctioneer.
Plan Petal and Evie's Wonderful Surprise Hugs has more details, takes advantage of Lilly's wide variety of powers, and explicitly commits to more thorough protections against Valerie's commands. A concern is that where Swiftness completely commits to its course of action, this plan is slightly more experimental in tone, and advocates waiting to gain the element of surprise, then executing a few more actions. Even with the possibility of traps or other things, I don't think this is ideal, given the time pressure and ceding the initiative to Valerie/Aboleath. As a pair, they're very prepared to hurt and torture others with no hesitation, even feeling amusement from it. Waiting could also be bad for Lilly's nerves. The stakes, sheer stress and looming helplessness of the situation are going to be an emotional obstacle.
For those reasons, Plan Petal and Evie's Wonderful Surprise Hugs is behind Plan: And with Swiftness--Swiftness Beyond Measure... by a hair, for me personally.
[X] Plan: And with Swiftness--Swiftness Beyond Measure...
-[X] {Subversion} You understand, nobody wants to be a murderer, she clearly said "Stop Me" just now, you'll do just that. (Altering a command by a single syllable)
--[X] Emergency Backup: Hand Control to Petal if you're running out of time, have her execute the next step as your proxy using {Relations}
-[X] Enter full Domain Perception mode, the Ladder warned you before and you ignored it, not twice--invoke {Sample Space} to guide your approach--at your full speed, that should be considerably less than even a second at this distance, gag her and cover her eyes to the best of your ability--don't be afraid to knock out some teeth or bloody her if need be, you can't afford to be gentle and you can fix it later. Once her voice is bound and her eyes aren't looking at anything you care for, follow {The Ladder}'s earlier instructions--extrude your Domain into her Heart and sever the occupying Entity.
-[X] When her voice is bound (Or ideally, she knocked out in some fashion, the point is that she be neutralized), extend Essence Links to your family to help handle the stresses of what she did, while you work on a means to break the command. Once confident in their safety, utilize {Slipstream} to deposit Valerie into Petal's care--the Ladder said the {Attuned Locus} and not the Dreamspace--and you don't think you can force someone in there yet anyway.
-[X] Everything is on the table here. This is not the time or place to be holding back.
[X] [SES] Shine, my Gentle Heart
[X] [BLU] At her lowest point, she found a hidden light.
[X] [BBLU] Her blood burned hot and thick, the enemy knew to avoid its scalding spray.
[X] [ACG] I Accepted the Trial.
[X] [AC] Inform the Captain that the Diviner is on to us and wants in. Ask him what he thinks of her, since he has a lot more professional interaction with her than we've had.
[X] [AC] After informing the Captain about the attack, ask Captain Martin about the feasibility of Communion Stones with him, his trusted lieutenants, and the Silas family. Being able to call for backup is a good option.
[X] [AC] It seems we have the personal attention of one of the forces of the apocalypse, because really, what else could an entity that can't be identified by the world be? This really should be more terrifying than it is, but it seems to just be our life now. Especially after that thing got into our Ethea selection.
-[X] Ask Evie what they know about that dude, and if they have any idea if all the things that hurt the same way are from the same source.
-[X] Discuss the Child and the Trial with Petal when you can. Even if she doesn't have any new insights, it's good to be able to tell someone. Even if it's just you, sort of.
[X] [AC] Talk to our family about the stuff we need to talk to them about (see: statues segment, those concerns) when we get a chance.
[X] [AC] Experiment with Minor Relation Slots later. There could be potential combat applications there.
[X] [AC] If your home is trashed or gory after fighting, ask Myah if she would like to wait before entering. No unnecessary trauma or poor hospitality for your friend and guest.
If we knew more about Minor Relation Slots, I'd advocate for trying something with Valerie. This is the best I can think of at the moment. Open to other unmentioned ideas here.
Next order of business for me is figuring out the Tests of Purity, Charity and Valor.
Valor feels like the ride toward Harmuph, or choosing to go into the Forest. Charity feels like giving Zach the chance for his Ethos. Purity is the iffiest, but I think it could be actively choosing to help Myah, rather than making her a tool. Not too confident about these. Also curious about the Weaver for this one.